Heat intensifier for boilers



Oct. 13, 1931.

w. F. McPHEE ET AL HEAT INTENSIFIER FOR BOILERS Filed May 11, 1928 Z a w@ w; am 5. mM fl W? I 7 Y U B 7 B p 1 r 5 3 9 0 n/v 6 z ATTORNEYJ Patented Oct. 13, 1931 ,UNITEDVI-STATES PATENT OFFICE WILLIAM F. MCPHEE AND HENRY c. KRUEGEB, or CHICAGO, ILLINOIS, AssIGNoRs, BY i MESNE ASSIGNMENTS, TO THOMAS H. HULBERT HEAT INTENSIFIER FOB BOILERS A pplication'filedjltay 11, 1928. "Serial No. 277,019. g

This invention relates to combustion devices according to which heated air is'supplied over the head of fuel in boilers, furnaces and the like in order to oxidize combustible gases in the firebox and thus generate more heat. Many different kinds of such devices have been suggested heretofore and are being used. 2 i The heating unit of such devices must ex- 10 tend substantially deeply'into the firebox in order to become heated to the high degree desired, namely,- substantially to redness. Usually the unit becomes at least a cherry red when the fire isburning with ordinary i intensity for heating purposes, and reaches an almost white heat under some conditions. One serious difliculty in theart hasbeen to devise a heating unit that would stand the effects of the high temperatures and the fluc- 20 tuations in temperatures encountered, and another has been to provide a high degree of eiiiciency especially at some of the lower temperatures, as when the fuel bed is burning at a relatively low rate and at which time the processes of distillation release valuable combustible gases which unless promptly oxidized are lost through the fiue stack. The prime objects of, the present invention'are 1 to improve the results in the directions just mentioned. Other objects and advantages will appear hereinafter.

In the drawingswhich form a part hereofv Figure 1 is a top plan view of our device as applied to a boiler.

Figure 2 is a section along theline 2=2 of Figure 1, v

Figures 3 and 4 are detail views of portions of our device, and

embodying thedevice. H j v In. carrying out our invention, we provide a unit 1 whichis composed of an outer casing 2 and an inner casing 33. The inner casing 8' is madeintegral with the outer casing2 through tubular connecting portions 4 and 5. Passageways 6 and 7 are provided in the portions 4 and 5, respectively," thus providing communication with the interior of the casing 3 which may be termed as a compartment 8. i

Figure 5 is a diagrammatic view of a boiler An air chamber 9 is provided in the outer casing 2 around the inner casing 3. An inlet opening 10 is provided for the air chamber 9.. A mouth portion .11 is provided integral 66 with the outer casing 2 and is provided with a relatively narrow'horizontally extending" outletopening 12. The ends of the outlet opening 12 taper or flare outwardly.

, The outer casing is provided with equally spaced ribbed portions 13 which extend from the passageways 6 and 7 about theouter periphery of the outer casing; The-inner wall of the outer casing is provided with trough-like recesses 1 1 positioned radially opposite the ribbed portions 13 respectively and extending in the same general direction.

The unit 1 is provided with a flange 15 which extends outwardly from the outer casing 2 about the inlet opening 10 and is rectangular in general contour.

A supporting member or frame 16' is provided with a substantially U-shaped retaining portion 17. The portion. 17 is provided with inwardly extending projections 18 overlying flanges 15 at the sides; An opening 19 is provided in the frame 16 in alignment with the inlet opening 10 of the unit 1. Side walls 20 and end walls 21 are provided'for the frame-16 and are arranged to be disposed T,

adjacent to a' door 22 of a boiler 23 and sccured'inplace by means ofbolts 24 or the 11m.)

From the foregoing description of the va rious parts of the device, the operationthereof may be readily understood. When the frame 16 issecured in place adjacent tothe inner wall of'the door 22, the group of inlet passageways 25 in the door is completely surrounded, whereby air, entering the boiler through the air passageways '25 must pass through the opening 19. r

The unitl may be secured to the framelfi so that the outlet opening 12 is substantially ina horizontal plane with respect to the opening 19. To secure the unit 1 to the frame '16 in this position, a straight key 26, see Figure 3, is disposed upon each side of the unit between the flange 15 and the inwardly extending projections 18.

When theumt 1 is in thisposition, the air ioo as it enters through the openings 25 will pass through the opening 19 and into the air Cl12LI11 her 9. Let us assume that there is a fire in the boiler. The heat from the lire within the boiler will heat the outer casing 2, and as the heat passes through the passageways 6 and 7 the inner casing 3 willalso become heated. Therefore, as the heat passes through the passageway 7, it will be received in the compartment 8, therefore heating the 1111181 casing. ing may be readily heated as well as the outer casing. Therefore, as the air passes-throughthe openings 25 and the opening 19 .into the chamber 9, it will beconieheated as it contactswith the wall of the outer and inner casings. The air in entering the chamber 9 willcontact with thein'ner casing-and pass around the inner casing to the outlet open ing'12. -The outlet opening 12 iselongated laterally and'is substantially narrow vertically, as will be observed from the dotted lines of Figure 2. Therefore,the air as it passes through the outlet opening 12 willbe spread or fanned out in a generally horizontal plane over the fire in the boiler.

It is sometimes desirable to direct the air upwardly as it-enters the-boiler so that it will not be directed into the fire or into the bed of coals. To accomplish this, the keys 26 may be removed and tapered keys, indicated at-Q'Z, may beinserted in their place.

The ribbed portions 13 provide a double function in that they not only reinforce the outer casing so as to prevent breakage, but they, in combination with-the 'concaved recesses, permit the outer casing to expand properly due to the intense heat.

In Figure 5 we have shown "an auxiliary means for heatingthe air before theair comes in contact with the interior of' the boiler. This auxiliary means consists in the provision of a pipe or tube'28 which'has one end in communication with the" steam. chest 29 of the-boilerand the'other end extending throughthc opening-19 and in communication with the chamber 9. In this manner steamis' allowed to pass into the chamber 9 so as to heat the air as it passes therethrough and into-the boiler. This is a valuable feature when breal-Iing upthe fire and applying fresh-fire in the 'boiler of a morning. Thus a spray of steam and air maybe spread over the fire and well-known advantages of such an introduction obtained. Further advantages are bad, however, over such as are ordinarilyobtained in that accordi-ngto these improvements inthis respect the air and steam are raised to a-hightemperature irn mediatel-ybe-fore they are discharged over the fuel'bed, and also in that the air and steam vapor are commingled with eachother in the device The outer and inner bodies 2-and 3 are showi'rasbeing-substantiallysphericahwhich In thisman-ner the inner-cits is the preferred form, although other bulbous formations are within the purview of this invention. An important feature of the improvement is in making both of these bodies, together with the tubular elements or devices 4 and 5, integral witheach other. To this end thedevice is preferably a casting of gray iron, but other fire-resisting compositions may be employed in moulded form. The spherical oroth'er bulbous form together witlr-th'eunitary -or integral construction makes for peculiar strength and resistance to the disintegrating and otherwlse destructive effects of the heat, since such a body does not 'breakand become distorted nearly as readily as .does a cylindrical or rectangular shape, and is less subject to t-he burning away of small formations such as corners. The integral formation strengthens the construction greatly against warping and cracking, and this, taken with the corrugations l31-i provides an. unusually satisfactory device in this respect. The recesses 14 are peculiarly important since the expansion strains are here given a directional outletor relief where they ma-yerpend themselves without objectionably distortingthe shell or body as a whole.

A notableimprovement is in the bulbous nature of the inner body 3 which provides a rcl'ativelylarge hollow interior adapted to contain a materially large body of the heated furnace gases and to delay thepassage of such gases through the device until their-heat units may be to a large extentabsorbed by the walls of the inner body. A further important feature is in the fact that the passageway9, substantially surrounding the inner body, is a radially shallow one,.and thus a substantially thin envelope 'of' air, or air and steam, is subjected, both outsideand inside the device, to the furnace heat. In other words there is an unusually large area of heatingsurface and an unusually shallow body of air to be heated at any given place. This makes for a high and unusual degree of efficiency, and at the same time the device has unusually long life in service.

We contemplate as being included in these improvements all such changes, departures and variations from what is thus specifically illustrated and described as fall within the scope of the appended claims.

We claim:

1. A combustion device-of the character described comprising walls forming a hollow bulbous outer body having anintake port and a oischarge port substantially at opposite ends of the body respectively and having means for securing the body to a furnace at an air intake opening thereof with such intakeopening in communication with said intake port and with said body extending into the-firebox of such boiler there being walls forming an inner hollow bulbous body within and spaced from the walls of the outer body to provide a substantially shallow passageway substantially surrounding the inner body and extending between and opening into said ports respectively, there being at least twotubular devices connecting the interior of said inner body with the exterior of said outer body at widely spaced-apart intervals circumferentially of the outer body for the purpose specified.

2. The combustion device of claim 1 hereof in which said inner and outer bodies and said tubular devices are all integral with each other.

v 3. The combustion device of claim 1 hereof in which said inner and outer bodies are sub- 7 stantially spherical and are, integral with I each other and with said tubular devices.

4. The combustion device of claim 1 hereof in which the walls of said outer body are of integral formation and are corrugated for the purpose specified.

5. The combustion device of claim 1 hereof in which said inner and outer bodies and 5 said tubular devices are all integral with each other and the walls of said outer body are formed with recesses extending in the same general direction for the purpose specified.

6. The combustion device of claim 1 hereof in which there are means for supplying live steam to said passageway between the inner and outer bulbous bodies to be discharged at said discharge port.

7. The combustion device of claim 1 hereof in which there are means for supplying live steam to said passagewaybetween the inner and outer bulbous bodies and in the form of a jet directed toward the discharge port and spaced from the adjacent walls of the outer 40 body to entrain air to be discharged with the steam at said discharge port.

Signed at Chicago, in the county of Cook, and State of Illinois this 7th day of May, A. D. 1928. a I WILLIAM F. MoPHEE. HENRY C. KRUEGER. 

